On Thursday, September 28, 2023 7:36 PM, Lucas Stach <l.stach@xxxxxxxxxxxxxx> wrote: > Otherwise the DMA enable races with the fetch start, which causes > wrong or no data to be scanned out on the first frame. Also there > is no point in waiting for the DMA disable when the controller is > going to shut down. Simply disable the display first so no further > fetches are triggered and then shut down DMA. > > Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > --- > v3: new patch > --- > drivers/gpu/drm/mxsfb/lcdif_kms.c | 23 ++++++++--------------- > 1 file changed, 8 insertions(+), 15 deletions(-) It seems that this one is the key to make fb pixel format change work ok for i.MX8mp LCDIF with modetest. However, there is about 20% probability to show constant color with the same test running on i.MX93 LCDIF. On top of this patch series, duplicating plane update in crtc atomic_enable like downstream driver does seems avoid the issue for i.MX93. Regards, Liu Ying
